Dross compression apparatus including a cooling system for cooling the compression head and cooling method

ABSTRACT

A cooling head for cooling material recovered from an industrial process when the material is disposed in a material container. The cooling head includes a downwardly projecting portion that is shaped to engage the material. A plurality of ribs may extend across a top of the cooling head.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent application Ser. No. 10/778,456, filed Feb. 13, 2004, which claims the benefit of U.S. Provisional Application Ser. No. 60/518,547, filed Nov. 7, 2003, the disclosures of which are herein incorporated by reference in their entireties.

FIELD OF THE INVENTION

This invention relates to a dross compression apparatus and more particularly to a cooling system and cooling method for more effectively cooling the compression head of a dross compression apparatus.

BACKGROUND OF THE INVENTION

Dross compression apparatus are commonly used to recover non-ferrous metals, particularly aluminum, from dross which has been skimmed from a furnace. Aluminum dross is a combination of aluminum metal and aluminum oxides, as well as other possible components such as various oxides, nitrates and carbides. Aluminum dross is a by-product of an aluminum melting operation. Generally the dross floats on top of the molten aluminum metal in the furnace. Aluminum dross may contain anywhere from ten percent to ninety percent aluminum depending on the particular processing technique and the type of furnace. Therefore the dross in an aluminum melting operation includes a significant amount of aluminum metal which is considered a valuable resource to be recovered.

The recovery of aluminum from aluminum dross must also address the problem of the loss of aluminum metal in the dross due to thermiting or thermite reaction, i.e., exothermic oxidation of aluminum metal. It is generally known to provide the compression head of the dross compression apparatus with air or water cooling to reduce the thermiting action and thereby increase the amount of aluminum recovered from the aluminum dross. However, there is a continuing need to be able to remove heat more effectively from the dross compression head to increase the capacity of the dross compression apparatus in recovering aluminum from aluminum dross or other non-ferrous metals from other drosses without the use of water cooling.

SUMMARY OF THE INVENTION

The compression head of the dross compression apparatus is more effectively cooled in accordance with the present invention by blowing cooling air across the top of the compression head during the recovery of various non-ferrous metals including aluminum from various types of dross.

In accordance with one aspect of the invention, one or more air nozzles are provided for directing cooling air across the top of the compression head.

In accordance with another aspect of the invention, one or more air vents are provided in the dross compression apparatus for venting the air after being directed across the top of the compression head.

In accordance with another aspect of the invention, a plurality of ribs may extend across the top of the compression head in the direction of the air vents for directing the air out of the air vents after being directed across the top of the compression head.

In accordance with another aspect of the invention, the air nozzles may direct air along and between the ribs on the top of the compression head toward the air vents.

In accordance with another aspect of the invention, the air nozzles may be movable in synchronism with the compression head during vertical movement of the compression head toward and away from the dross collector.

These and other objects, advantages, features and aspects of the present invention will become apparent as the following description proceeds.

To the accomplishment of the foregoing and related ends, the invention, then, comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawings setting forth in detail a certain illustrative embodiment of the invention, this being indicative, however, of but one of the various ways in which the principles of the invention may be employed.

BRIEF DESCRIPTION OF THE DRAWINGS

In the annexed drawings:

FIG. 1 is a schematic front elevation view of the dross compression apparatus of the present invention showing air vent slots in a back wall of the apparatus.

FIG. 2 is a schematic fragmentary side elevation view of the dross compression apparatus of FIG. 1 showing air nozzles connected to an air manifold for blowing air across cooling ribs on the top of the compression head and out air vent slots in a wall of the apparatus.

FIG. 3 is a schematic top plan view of the compression head and air manifold with air nozzles connected thereto of FIG. 2.

FIG. 4 is a front elevation view of the compression head of FIGS. 2 and 3.

FIG. 5 is an enlarged schematic perspective view of the air manifold and air nozzles of FIGS. 2 and 3.

FIG. 6 is a schematic side elevation view of one form of dross compression apparatus of the present invention.

FIG. 7 is a schematic back elevation view of the dross compression apparatus of FIG. 6.

FIG. 8 is a schematic top plan view of the dross compression apparatus of FIG. 6.

FIG. 9 is a perspective view of a cooling system in accordance with one exemplary embodiment of the present invention.

FIG. 10 is a perspective view of a cooling system in accordance with another exemplary embodiment of the present invention.

FIG. 11 is a perspective view of a multi-chamber cooling system in accordance with another exemplary embodiment of the present invention.

FIG. 12 is a perspective view of a cooling system in accordance with another exemplary embodiment of the present invention.

FIG. 13 is a front view of a cooling head in accordance with an exemplary embodiment of the present invention.

FIG. 14 is a front view of a cooling system in accordance with an exemplary embodiment of the present invention where a skim pot and a sow mold are shown in section.

FIG. 15 is a side view of a cooling head in accordance with another exemplary embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring now in detail to the drawings wherein like reference numerals are used to indicate like parts, and initially to FIG. 1, there is schematically shown one form of dross compression apparatus 1 in accordance with the present invention which may be generally of the type disclosed in U.S. Pat. Nos. 5,397,104 and 5,669,957, the entire disclosures of which are incorporated herein by reference. Such apparatus includes a compression head 2 that may be driven vertically by a suitable drive means such as a fluid piston/cylinder 3 toward and away from a dross collector 4. Alternatively, the drive means may drive the dross collector 4 toward and away from the compression head 2 or drive both the compression head and dross collector toward and away from one another. Any suitable drive means may be utilized for this purpose including hydraulic, pneumatic, electrical or other drive means.

Dross collector 4 may have a substantially hemispheric shaped receptacle 5 and compression head 2 may be similarly shaped to cooperate with the receptacle. The term substantially hemispheric shaped as used herein is broadly defined to mean any shape that is substantially similar in concept and function to the shapes shown in the drawings and includes shapes that deviate from the shapes shown such as flatter structures or more pointed structures as well as structures that may have additional curved surfaces.

The dross collector receptacle 5 is provided with one or more openings (not shown) at the bottom of the receptacle to allow molten aluminum (or other molten metal) to pass by gravity and under the pressure of compression head 2 out from the collector into a lower receptacle 6 which is referred to in the art as a sow mold. Dross collector 4 may be provided with tubular members 7 for receipt of the forks of a forklift truck for transporting the dross collector 4 from a furnace to the dross compression apparatus and removal therefrom.

The compression head 2 of the present invention may be made of any suitable solid metal such as cast alloy steel to provide sufficient mass for dissipating heat in the dross metal during the recovery of various non-ferrous metals from various types of dross, including particularly aluminum from dross which has been skimmed from a furnace. Multiple ribs 10-12 may be provided on the top 15, bottom 16 and sides 17 of the compression head as schematically shown in FIGS. 2-4. As used herein, the term rib means broadly any projection or shape which forms a projection, raised area, ridge, corner or non-continuity on the compression head.

The ribs 11 and 12 on the bottom 16 and sides 17 of compression head 2 extend into the dross in the dross collector or skim box 4 during the recovery process to help dissipate the heat in the dross metal. Also such ribs may help increase the compressive force on the dross metal as disclosed in the aforementioned U.S. Pat. Nos. 5,397,104 and 5,669,957.

The ribs 10 on the top 15 of compression head 2 also help to remove heat from the compression head. To remove heat more effectively from the compression head, cooling air may be blown across the top of the compression head during and between relative vertical movements of the compression head and dross collector toward and away from each other. These ribs 10 extend generally in the same direction, for example, from the front of the apparatus toward the back, to help channel cooling air that is blown across the top of compression head 2 out through air vent slots 18 (see FIGS. 1-3 and 7) in a wall 19 of the dross compression apparatus.

Cooling air may be directed along the peaks 20 and valleys 21 of ribs 10 by a plurality of vortex nozzles 22 supported by an air manifold 23. If the compression head is mounted for vertical movement, the air manifold 23 and associated air nozzles 22 may be raised and lowered in synchronism with the raising and lowering of the compression head 2 so that the air is always directed across the top of the compression head and not onto the dross metal which would cause the dross metal to oxidize.

Suitable slides or the like (not shown) may be provided on the air manifold 23 for engagement with vertical rails or the like on the frame of the dross compression apparatus for guiding the air manifold during its vertical movement. Also a suitable mechanism such as a piston/cylinder 25 that is used to move the air manifold 23 vertically may be controlled by the same controller 26 (see FIGS. 7 and 8) that is used to control the vertical movements of the compression head 2 for causing the air manifold and associated air nozzles 22 to move in unison with the compression head.

Suitable hoses 30 may connect the air nozzles 22 to the plenum chamber 31 of the air manifold 23 as schematically shown in FIG. 5. Air manifold 23 may be supplied with pressurized air through a hose 32 from a suitable air supply such as compressed air or air received from a blower at a remote site.

The number, size and location of the air vent slots 18 in wall 19 of dross compression apparatus 1 should be such that substantially all of the cooling air passing over the top of the compression head is discharged through the slots to minimize oxidation of the dross metal. Air vent slots 18 may all be of about the same length and may match the peaks 20 and valleys 21 formed by the ribs 10 on the top of compression head 2 in number and location. If the wall 19 of dross compression apparatus 1 in which the slots are provided contains a small door 35 used to provide access for cleaning the compression head, the slots 18 may also extend through portions of the door as schematically shown in FIG. 7 to aid in the venting of substantially all of the cooling air from the dross compression apparatus after passing over the top of the compression head.

In operation in accordance with the method of the present invention, dross is collected from an electric furnace or the like in the receptacle 5 of the dross collector 4 and then transported to the dross compression apparatus 1. With the lower receptacle or sow mold 6 in place, metal, particularly aluminum, is allowed to decant through an opening in the lower end of the dross collector 4 into the sow mold. Then, after the main door 36 (see FIG. 8) of the dross compression apparatus is closed, the compression head 2 is moved toward the dross collector receptacle 5 to compress the dross. At the same time, the ribs 11 and 12 on the bottom 16 and sides 17 of the compression head 2 form grooves in the shell of material between the compression head and the inner surface of the receptacle as disclosed in the aforementioned U.S. Pat. Nos. 5,397,104 and 5,669,957 enabling the shell to be easily broken for further processing such as by crushing.

The cooling air that is directed by the vortex nozzles 22 across the top of the compression head 2 during compression of the dross will lower the temperature of the compression head and maximize the cooling effect of the air on the compression head. Removing the heat from the compression head while the compression head is compressing the dross material during the recovery process increases the capacity of the dross compression apparatus without the need for water cooling. The cooling capacity of the compression head of the present invention may be as much as four times that of a standard compression head. For example, a dross compression apparatus incorporating the compression head cooling system of the present invention that normally presses three to four containers of dross metal every three to four hours would be able to press three to four containers of the dross metal every hour.

With reference to FIGS. 9 through 15, various exemplary embodiments of a cooling system 37 are shown. The cooling system 37 may be used to cool a variety of materials including, for example, aluminum dross, dross from other metal processing, salt cake and so forth. The material may be residue obtain following the recovery of molten aluminum from a recycling operation or from some other industrial process, such as, without limitation, byproducts from a magnesium processing system and chloride flux derived from a paper pulp processing system. As will be appreciated, these materials are preferably cooled prior to disposal or further processing.

The cooling system 37 includes a cooling head 38. The cooling head 38 may be placed on a material container 39. The cooling head 38 and material container 39 have corresponding geometries to cooperate with one another in the manners described herein. Depending on the application, the material container 39 may be referred to as a dross collector (e.g., the dross collector 4 of FIGS. 1 and 6-7), a skim pot, and so forth. The cooling head 38 and/or the material container 39 may be made from any appropriate material, including cast alloy steel or grey iron. Grey iron may be cheaper than alloy steel, but alloy steel may be more resistant to surface checking and cracking and, as a result, have a longer life-span. Allow steel also may more efficiently cool the material.

The material container 39 may have a receptacle 40 for the material to be cooled. In the embodiment of FIG. 11, the material container 39 has plural receptacles 40. In one embodiment, the receptacle 40 and/or a portion of the cooling head 38 that projects into the receptacle 40 may be substantially hemispheric shaped. Of course, other shapes are possible.

In some configurations, the material container 39 may be provided with one or more openings 41 (best shown in FIG. 14) at the bottom of the receptacle 40 to allow molten aluminum (or other flowable material) to pass by gravity and/or under the pressure from the cooling head 38. The substance passing through the openings 41 mat be collected in a collector pan 42 disposed under the material container 39. Depending on the industrial application, the collector pan 42 may be referred to as a drain pan or a sow mold.

The material container 39 and/or the collector pan 42 may include passages 43 that accept forks of a forklift truck for transporting the material container 39 and/or collector pan 42. In one embodiment, the cooling head 38 may include tubular members 44 for receipt of the forks of a forklift truck for transporting the cooling head 38 and/or positioning the cooling head 38 on the material container 39. In another embodiment, the cooling head 38 may be wider than the material container 39 and the forks of the forklift truck may move and/or position the cooling head 38 by engaging portions of the cooling head 38 that overhand the material container 39. In yet other embodiments, the cooling head 38 may be moved and/or positioned with respect to the material container 39 using a hoist or crane. The cooling head 38 may include a hook(s), ring(s) or other member for facilitating coupling of the cooling head 38 to the hoist or crane by way of, for example, a rigid member, a cable, a chain, a hook, and so forth. In one embodiment, such as the embodiment shown in FIG. 12, the cooling head 38 may be coupled to a lever arm 45. The lever arm 45 may be raised and lowered (and possibly swung) to position the cooling head 38 with respect to the material container 39. In the illustrated embodiment, the elevation of the lever arm 45 is controlled by a hydraulic piston, but other mechanisms for positioning the lever arm 45 are possible. The lever arm 45 may connect directly to the cooling head 38 or may connect to the cooling head 38 by way of a rigid member, a cable, a chain, a hook, a ball joint, a spring and/or some other member. The lever arm 45 may be mounted to a stationary frame.

The cooling head 38 may have a downwardly projecting protrusion 47. As illustrated, a plate-like member that forms an upper portion 48 of the cooling head 38 has a depression, or well, that forms the protrusion 47 by protruding downwardly for making thermal contact with the material. The upper surface of the upper portion 48 may be depressed so that the lower surface of the protrusion 47 is convexly curved and is disposed below the surrounding flange-like members formed by the upper portion 48. In some embodiments, the protrusion 47 may be substantially hemispheric shaped. When the cooling head 38 is positioned on the material container 39, the protrusion 47 may enter the receptacle 40 though an open top of the material container 39 and the protrusion 47 may contact the material contained in the material container 39. The cooling head 38 may include multiple protrusions 47, such as a protrusion 47 for each receptacle 40 of a multi-receptacle 40 material container 39 (e.g., the cooling head 38 and the material container 39 of FIG. 11).

Heat from material contained in the material container 39 may be transferred to the protrusion 47. A substantial amount of the transferred heat may be conveyed to the upper portion 48 of the cooling head 38. In one embodiment, the upper portion 48 of the cooling head 38 may be a plate that surrounds the protrusion 47. In the illustrated embodiments, the upper portion 48 is open so that a recess formed by the protrusion 47 is open to the environment. This open recess, or well, creates surface area for efficient heat transfer and provides a lighter cooling head 38 relative to a cooling head 38 that has a solid protrusion 47 or a covered protrusion 47. The surface of the well (which is the upper surface of the protrusion 47) may be relatively smooth as shown or have structural elements (e.g., ribs).

The lower surface of the protrusion 47 may be relatively smooth as shown in FIGS. 9 through 12. Alternatively, the lower surface of the protrusion 47 may have structural elements, such as ribs 49 as shown in FIGS. 13-15. Again, as used herein, the term rib means broadly any projection or shape which forms a projection, raised area, ridge, corner or non-continuity on a surface. Ribs also may be referred to as fins or flanges. Similar to the ribs 11-12, the ribs 49 may extend into the material in the material container 39 to help dissipate and/or transfer the heat in the material. Also, such ribs may help increase the compressive force on the material. In the exemplary embodiments of FIGS. 9-15, the cooling head 38 is placed on the material container 39 and any compression of the material in the material container 39 is achieved solely by the weight of the cooling head 37 acting on the material. In other embodiments, downward force may be applied to the cooling head 38 to achieve compression of the material. Such downward force may be applied, for example, using a press assembly, such as the above-described dross compression apparatus 1. In other embodiments, downward force may be applied by a forklift truck or the lever arm 45 used to move the cooling head 38.

To assist in dissipating and/or radiating heat from the material to the environment, the cooling head 38 may include structural elements on the upper surface of the upper portion 48. For instance a series of ribs 50 may be present. The tubular member 44, if present, also may serve to assist in dissipating and/or radiating heat. In effect, the ribs 50 and/or other elements on the top of the cooling head 38 may help to remove heat from the cooling head 28. To enhance the removal of heat from the cooling head 38, cooling air may be directed across the top of the cooling head 38. For instance, as shown in FIG. 10, a blower 51 or other ventilation system may draw air across the top of the cooling head 38 as graphically portrayed by arrow 52. In other embodiments, the air may be blown across the top of the cooling head 38. Plural cooling systems 37 may be arranged in close proximity to each other such that air may be directed across multiple cooling heads 38 to assist in cooling material that is dispensed into multiple corresponding material containers 39.

The ribs 50 on the cooling head 38 may extend generally in the same direction, such as from the front of the cooling head 38 toward the back of the cooling head 38 (e.g., as shown in FIGS. 9-10 and 12-15) or from one side to another side (e.g., as shown in FIG. 11). The directionality of the ribs may help channel cooling air that is directed across the top of the cooling head 38. For instance, cooling air may be directed along the peaks 53 and valleys 54 of the ribs 50 as best illustrated in FIGS. 13 and 14. Any suitable nozzle assembly, blower, manifold, fan or air circulator may be used to create an air flow to assist in removing heat from the cooling head 38. If the cooling head 38 is mounted for vertical movement, such as when used as a compression head for a compression apparatus, the air directing mechanism may be raised and lowered in synchronism with the raising and lowering of the cooling head 38.

A lower surface of upper portion 48 may be configured to engage an upper edge of material container 39. The interface (or closure) between the cooling head 38 and material container 39 may reduce the flow of gasses into the receptacle and reduce oxidation of the material in the material container 39 during cooling. As indicated, edge portions of the upper portion 48 may overhang the material container 39. Overhanging portions 55 may be bent downward to enhance the sealing effect, to divert air flow and/or to provide a lip to assist in stabilizing the cooling head 38 in embodiments where a forklift is used to lift the underside of the cooling head 38. The downwardly bend overhanging portions 55 may be present on any combination of the front edge, the rear edge, the left side edge and the right side edge.

The well formed by the protrusion 47 may be filled with a material to assist in weighting the cooling head 38 and/or adjusting the cooling behavior of the cooling head 38. For instance, sand, metal shot, plates or a conforming metal insert may be placed in the well. Also, a cooling apparatus may be placed in the well. In other embodiments a coolant (in addition to or instead of the above-described air) may be directed across the surface of the recess and/or the ribs 50. For instance, water or oil may be circulated with respect to the cooling head 38.

In an exemplary industrial application to process aluminum dross, a compression apparatus (e.g., the compression apparatus 1) may be used to compress dross in a time period of about an hour or less. Then, the container in which the dross was compressed may be moved from the compression apparatus and a cooling head (e.g., the cooling head 38) may be placed on the moved dross and dross container to further cool the dross for a period of time, such as about one hour to about two hours. This allows for increased use of the compression apparatus for compression, which leads to increased throughput and process efficiencies.

Although the invention has been shown and described with respect to certain embodiments, it is obvious that equivalent alterations and modifications will occur to others skilled in the art upon the reading and understanding of the specification. In particular, with regard to the various functions performed by the above described components, the terms (including any reference to a “means”) used to describe such components are intended to correspond, unless otherwise indicated, to any component which performs the specified function of the described component (e.g., that is functionally equivalent), even though not structurally equivalent to the disclosed component which performs the function in the herein illustrated exemplary embodiments of the invention. Also, all of the disclosed functions may be computerized and automated as desired. In addition, while a particular feature of the invention may have been disclosed with respect to only one embodiment, such feature may be combined with one or more other features as may be desired and advantageous for any given or particular application. 

1. A cooling head for cooling material recovered from an industrial process when the material is disposed in a material container, comprising a downwardly projecting portion that is shaped to engage the material and a plurality of ribs extending across a top of the cooling head.
 2. The cooling head of claim 1, wherein the material is aluminum dross.
 3. The cooling head of claim 1, wherein the downwardly projecting portion includes ribs on a lower surface thereof.
 4. The cooling head of claim 1, wherein a lower surface of the cooling head is configured to engage an upper edge of the material container so as to rest thereon during cooling of the material.
 5. The cooling head of claim 1, further comprising tubular members configured to receive forks of a forklift truck for moving of the cooling head.
 6. A cooling system, comprising: the cooling head of claim 1; a material container; and a lever arm moveable to lower the cooling head onto the material container and lift the cooling head off of the material container.
 7. A cooling system, comprising: the cooling head of claim 1; a material container, the cooling head disposed on the material container; and a means for directing cooling air across the top of the cooling head and between the ribs for cooling the cooling head.
 8. A cooling system, comprising: the cooling head of claim 1; a material container having holes for draining a liquid component of the material, the cooling head disposed on the material container; and a collector pan disposed under the material container for collecting the drained liquid component.
 9. A dross compression apparatus, comprising: the cooling head of claim 1; and a drive means for vertically moving the cooling head and forcing the cooling head into material retained by a material container to compress and cool the material.
 10. The dross compression apparatus of claim 9, further comprising a means for directing cooling air across the top of the cooling head and between the ribs for cooling the cooling head.
 11. The dross compression apparatus of claim 9, wherein the material is aluminum dross.
 12. A method of cooling material recovered from an industrial process, comprising: placing the material into a material container; and placing a cooling head with respect to the material container so that a downwardly projecting portion of the cooling head engages the material and heat is radiated from a plurality of ribs extending across a top of the cooling head.
 13. The method of claim 12, wherein the material is aluminum dross.
 14. The method of claim 12, wherein the downwardly projecting portion includes ribs on a lower surface thereof.
 15. The method of claim 12, wherein a lower surface of the cooling head is configured to engage an upper edge of the material container so as to rest thereon during cooling of the material.
 16. The method of claim 12, wherein the cooling head is lowered into contact with the material with a lever arm.
 17. The method of claim 12, further comprising directing cooling air across the top of the cooling head and between the ribs to cool the cooling head.
 18. The method of claim 12, further comprising collecting a liquid component of the material that drains through holes of the material container with a collector pan.
 19. The method of claim 12, further comprising forcing the cooling head into the material to compress and cool the material.
 20. The method of claim 19, directing cooling air across the top of the cooling head and between the ribs to cool the cooling head.
 21. The method of claim 12, further comprising compressing the material with a compression head of a compression apparatus before placing the cooling head with respect to the material container. 